The active matrix organic light emitting diode display (AMOIED) has been widely used due to the advantages such as wide viewing angle, good color contrast effect, fast response speed and self illumination.
AMOIED primarily employs low temperature poly-silicon as the driving layer to enable its pixel driving circuit. Compared to the general amorphous silicon technology, the low-temperature poly-silicon thin film transistor is characterized by higher mobility and better stability, which is more suitable for AMOLED display.
However, due to the characteristics of the backplate process and poly-silicon, the low-temperature poly-silicon backplate inevitably leads to difference in threshold voltages of the very close transistors. This would cause the display brightness of different pixels to be different when they receive the same data signal, thereby resulting in non-uniform display of the display panel.